1. Field of the Invention
The present invention relates to a device for preparing an end of a tubular structure, such as a blood vessel, which is to be anastomosed, and more particularly to an anastomosis trimming device.
2. Description of the Prior Art
Heretofore in the field of cardiovascular surgery, when it has been necessary to perform an anastomosis, i.e., to suture two blood vessels together while assuring that the lumen remains open, the shaping of the anastomotic end of the vessels has usually been achieved by the use of scissors.
With respect to forming an anastomosis, it is to be noted that one of the vessels is usually the patient's blood vessel and the other vessel may be a blood vessel or tissue graft from the same patient, a synthetic graft, a biograft, a homograft, a heterograft, a renograft, or a biosynthetic graft.
Further, it is to be noted that for preparing the end surfaces which are to be joined together in an anastomosis procedure, particular matched geometries are required for the ends of the vessels to be anastomosed end-to-end for reduction of potential weakness or leakage in the area of the anastomosis. By geometry, one means various shapes of cuts applied to the anastomotic ends, the geometry generally being dictated by the type of anastomosis to be performed, and by the location in the body where the anastomosis is to be formed.
Difficulties have presented themselves when the ends of graft structures are manually trimmed with scissors, inasmuch as such scissor trimming technique lacks exact reproducibility and therefore provides a variability between opposed ends, i.e. inexact mating within the anastomotic site, such inexact mating causing a potential site of leakage.
Various geometries of cut, i.e. straight cut, sigmoid cut, spatulate cut, and the ratio of the lumen's longitudinal diameter to the diameter of the graft, all dictate the necessity of the provision of a device which will allow for reproducibility when trimming ends of vessels and/or synthetic graft structures which are to be joined. In this respect, unless the vessel is cut with one continuous stroke, nicks and irregularities can result. Such irregularities can produce a site of tearing or leakage when high internal pressures are applied, or after a prolonged period of use. When trimming a vessel in-situ, and most significantly when a sigmoid shape is required, maneuvering scissors in such a restricted area will provide difficulties in achieving a smooth end surface, especially if the vessel to be cut is thickwalled.
It is therefore desirable that the anastomosis trimming device of the present invention provide a compact, easily manipulated means for cutting or trimming the ends of blood vessels or grafts with the shape of the end cut or trim being reproducible onto each anastomotic end of the structures that are to be connected end-to-end in an anastomotic manner.
Further, the anastomosis trimming device can be utilized in providing a smooth cut end for use in bypass procedures, where end-to-side anastomoses are required. The anastomosis trimming device can also be used for trimming other tubes or conduits such as ureters, urethras and the like.
In particular, the anastomosis trimming device of the present invention provides a cutting die incorporating a cutting element and, preferably, an opposed, mating element, such as a seat member, anvil, or cutting element, specifically providing for uniformity of cuts at the ends of the structures to be anastomosed, with the geometry of the cutting element of the cutting die utilized dictating the reproducible shape of the anastomotic ends. The anastomisis trimming device can be made inexpensively from one molded piece and can be discarded or it can be resterilized for multiple uses.